Poisonous Yellow Flower Weed. Yellow star thistle is an annual weed that branches out from a single base stem to form a spherical plant up to three feet tall. Perilla is usually found in shady areas around forest edges and farm buildings.
It is often confused with American bittersweet and Oriental bittersweet plants. Relatively few people can identify bittersweet nightshade on their property. The whole plant especially the flowers is toxic.
Although it is a perennial plant it spreads from seed and germinates throughout the year.
The seeds are wind-borne and often found germinating along the edges of garden borders. While these names identify it as a plant poisonous to dogs specifically dogbane is actually considered poisonous in a more general sense toxic to other life forms as well. Its erect stiff stems grow two to three feet high and are covered with gray hairs and its thistlelike flowers range from. Relatively few people can identify bittersweet nightshade on their property.